Threonine is an essential amino acid in humans. It is abundant in human plasma, particularly in newborns. Severe deficiency of threonine causes neurological dysfunction and lameness in experimental animals. Threonine is an immunostimulant which promotes the growth of thymus gland.
The Union Pacific Railroad, Building America. The Union Pacific (UP) is one the largest and most powerful railroads in the country. This historic system has been in operation since before the Civil War and much of the general public has at least a general knowledge of UP since it formed the eastern segment of the Transcontinental Railroad.
Making the world better, one answer at a time. The biggest railroad currently is the UP (Union Pacific). Next in line would be BNSF (Burlington Northern Santa Fe), then NS (Norfolk Southern) and finally CSX. The biggest railroad in US history is most likely Penn Central (because the biggest railroad before, the Pennsylvania Railroad, and the New York Central Railroad merged and made one large railroad). The biggest railroad currently is the UP (Union Pacific).